[PATCH] D24940: [thinlto] Add cold-callsite import heuristic

[Mehdi AMINI via llvm-commits]

mehdi_amini added inline comments.

================
Comment at: lib/Transforms/IPO/FunctionImport.cpp:296
@@ +295,3 @@
+      BonusMultiplier = ImportHotMultiplier;
+    else if (Edge.second.Hotness == CalleeInfo::HotnessType::Cold)
+      BonusMultiplier = ImportColdMultiplier;
----------------
Prazek wrote:
> mehdi_amini wrote:
> > Oh I see why you did it. Maybe a static function close to the cl::opt?
> > 
> > `const float BonusMultiplier = getBonusMultiplierForHotness(Edge.second.Hotness);`
> > 
> > (Straw man naming)
> what about
>   auto GetBonusMultiplier = [](CalleeInfo::HotnessType Hotness) {
>       if (Hotness == CalleeInfo::HotnessType::Hot)
>         return ImportHotMultiplier;
>       if (Hotness == CalleeInfo::HotnessType::Cold)
>         return ImportColdMultiplier;
>       return 1.0;
>     };
>     
>     const auto NewThreshold = Threshold * GetBonusMultiplier(Edge.second.Hotness);
That's fine with me.

(I wouldn't use a lambda as there is not much value seeing this boilerplate when reading this loop body, but I don't mind if you prefer it).


https://reviews.llvm.org/D24940